Method for forming a reinforced fiberboard container

ABSTRACT

A reinforcing liner of improved design is quickly and easily attached to the outer box blank as a part of the formation of the fiberboard container.

nite States 0010 i191 Ellison METHOD FOR FORMING A REINFORCED FIBERBOARD CONTAINER [75] Inventor: Donald E. Ellison, Clayton, Ind.

[73] Assignee: Inland Container Corporation,

Indianapolis, Ind.

22 Filed: Aug.28,1972

[21] Appl. No.: 283,952

52 us. C1 229/14 BA, 93/366 [51] Int.C1 ..B65d 25/14 [58] Field of Search 229/14 BA, 14 BL, 14 BW; 93/3601, 36.6, 37 SP [451 Aug. 13, 1070 [56] References Cited UNITED STATES PATENTS 2,801,782 8/1957 lngham 229/14 BW 3,281,050 10/1966 Suchodolski 229/14 BA Primary Examiner-Wi11iam 1. Price Assistant Examiner--D. B. Farrow Attorney, Agent, or Firm- Fitch, Euen, Tabin & Luedeka [57] ABSTRACT A reinforcing liner of improved design is quickly and easily attached to the outer box blank as a part of the formation of the fiberboard container.

10 Claims, 4 Drawing Figures METHOD FOR FORMING A REINFORCED FIBERBOARD CONTAINER The present invention relates to reinforced containers and more particularly to very large fiberboard containers which are adapted to contain large amounts of flowable materials.

Fiberboard containers may be utilized to ship large amounts of flowable material e.g., 2,000 pounds of semisolid substances. Commonly, such containers are reinforced to prevent rupture of their fiberboard panels by the pressure forces created by their flowable contents. One method of reinforcing such a container is to provide the container with a reinforcing liner which is affixed to the interior panels of the container. Such a liner may be a four-panel strip of corrugated fiberboard which generally conforms in size to the interior panels of the container.

A typical method of manufacturing such a reinforced container might involve placing a flat, continuous liner blank on the interior surface of a regular slotted container blank in a generally overlying congruent relationship thereto. Typically the liner is fixed to the interior surface of the container panels by glue. The reinforced container is then folded, and the manufacturers joint formed as with a regular slotted container.

However, for very large, bulk containers it may be uneconomical to produce and handle a liner which is formed of a single sheet of corrugated fiberboard with four panels joined side-by-side in a straight line. For a very large bulk container, a continuous sheet which would extend the full length of the perimeter of the container might exceed the manufacturing capacity of some corrugating machines, if it were desired to have the flutes run horizontally. In such an instance, two separate two-panel blanks are often used to form the liner. These blanks are generally placed one atop the other in the fabrication process, the two liner blanks overlaying the two central panels of the slotted container blank. Adhesive is usually provided on the interior surfaces of the container panels, and the container is completed by forming the manufacturers joint. It is a disadvantage of such an arrangement that two liner blanks both must be manually positioned in an accurate manner with respect to the container blank. As manual labor is a significant aspect in container manufacture, it is relatively expensive to accurately position two liner blanks on the outer container blank rather than just one liner blank.

It is the object of the present invention to provide an improved method of forming a reinforced fiberboard container.

It is another object of the invention to provide an improved blank design for forming a reinforcing liner for a fiberboard container.

These and other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the accompanying drawings of which:

FIG. I is a plan view of a liner blank having features of the present invention;

FIG. 2 is a perspective view of the blank of FIG. 1 folded in half and placed on a regular slotted container blank;

FIG. 3 is an end view of a container of FIG. 2 after the manufacturers joint has been formed, being shown partially set-up; and,

FIG. 4 is an enlarged fragmentary view of a detail of the container of FIG. 3.

The present invention shall be discussed in conjunction with a regular slotted container blank which is denoted as ll. The container blank 11 is in the shape of an elongated rectangle in plan and is formed from corrugated fiberboard which is slotted and scored to provide two matching end panels 13a and 13b, two matching side panels 15a and 15b, upper and lower closure flaps l7 and a flap 19 for forming a manufacturers joint. Longitudinal score lines 25 extend parallel to the edges 23 and define the fold lines along which the flaps 17 are connected to the side and end panels. Six slots 21 each extend transversely from the longitudinal edges 23 of the blank 11 to the longitudinal score lines 25 at predetermined intervals to form the closure flaps l7. Transverse or vertical score lines 27a, b, and 0 extend between the slots 21 and complete the definition of the end panels 13 and side panels 15. The glue flap 19 is connected along a score line 27a to the end panel 13b.

The illustrated liner blank 31 is in the shape of an elongated rectangle in plan and is formed of corrugated fiberboard with the flutes running longitudinally. The two minor side edges 33 of the blank are of a length which is approximately double the vertical dimension or depth of the container to which the blank is to be fixed. The horizontal or longitudinal edges 35 of the blank 31 are of a length slightly less than one-half the length of the inner perimeter of the subject container.

A longitudinally extending cut or slit is parallel to the horizontal edges 35 of the blank and spaced midway therebetween. The slit 37 extends from a point adjacent but spaced from one side edge 33 to a point adjacent but spaced from the other side edge 33. The unsevered portions of the blank 31 adjacent the ends of the slit 37 provide what is hereinafter referred to as the attachment regions 38.

The illustrated blank is scored between the ends of the slit 37 and the side edges 33 to provide short score lines 41 which are colinear with the slit 37. Although score lines are spoken about generally hereinafter, it should be understood that other means of creating a line of weakness in the attachment regions 38 may be used, or if the distance is short enough, it may be possible to simply omit any treatment of these short attachment regions and rely upon the inherent character of the corrugated liner to fold in a continuation of the slit 37. Transverse score lines 43 are provided on the blank 31 in locations where, when folded, they will be aligned with the score lines 27b and 27d of the container blank 11 to which the liner 31 is to be affixed, each half of the blank having one end panel reinforcement portion 45 and one side panel reinforcement portion 47.

In FIG. 2, the liner blank has been folded in half about the slit 37, the score lines 41 at the ends of the slit assisting in this folding. In forming the reinforced container, adhesive is preferably applied to the inner surfaces of the container blank panels, but it may alternatively be applied to the outer surfaces of both halves of the liner blank 31. The folded liner blank 31 is positioned on the regular slotted container blank 11 with the score line 43a aligned with the fold line 27b so that the end panel reinforcement portion 45a overlies the central end panel 13a of the container blank and the side panel reinforcement portion 47a overlies the central side panel 15a of the container blank. Alignment of the two panels 45a and 47a of the folded liner upon the container blank automatically locates the upper two panels 45b and 47b in their proper position. No other step or effort is required with respect to the liner, and manufacture of the container may be completed in the usual manner.

To complete the fabrication of the container, the outermost end panel 13b and side panel 15b of the container blank are folded over the end 45b and side 47b panel portions of the folded liner blank. The manufacturers joint is then suitably formed, and manufacture of the reinforced container is complete. Preferably, adhesive is applied to the glue flap 19 at the same'time as the adhesive pattern is applied to the end and side panels of the blank 11.

When the reinforced container is squared or set-up, the spreading of the sides of the container, as illustrated in FIG. 3, cause the adjacent panels of the liner to move apart, tearing the attachment regions 38 of the liner 31 adjacent the slit 37. As the panels of the liner approach their squared alignment, stress is concentrated at the end points of the slit 37, the forces seeking to elongate the slit. The score lines 4-1 assist in concentrating these tearing forces, and the attachment regions 38 are torn generally along the score lines, enabling the container to assume its squared disposition depicted in FIG. 4. As the attachment regions 38 of the liner 3! are very short preferably not greater than about an inch long, tearing is easily accomplished, generally along the short score lines 41. The attachment regions 38 have as their sole function to keep the halves of the liner in a fixed relationship to each other during the formative stages of the container. This in turn enables both liner halves to be easily handled and quickly positioned on the container blank 11 as a single unit.

The attachment regions 38 of the liner 31 should be of a length such that when the box is set up or squared, they will be easily torn, yet these attachment regions should possess sufficient strength to maintain the two liner halves together in their folded configuration while the container is being manufactured. For example, a liner 3] for a bulk container having a sidewall 15 about 5 feet long and an end wall 13 about 3 feet long may have unsevered attachment regions 38 adjacent the slit 37 which are each approximately /2 inch in length.

Thus, it is no longer necessary for the assemblyman to assure that two liner halves are each properly positioned on the outer container blank and held in this position until the reinforced container is formed by completing the manufacturers joint. The assemblyman need only position the one-piece, folded liner on the container blank where the tack of the adhesive will aid in maintaining it in its proper position.

While one embodiment of the invention has been shown and described it should be apparent that various modifications may be made therein without departing from the spirit and scope of the invention. Various of the features of the present invention are set forth in the claims which follow.

What is claimed is:

l. The method of forming a fiberboard container having a reinforcing fiberboard liner, which method comprises providing a rectangular liner blank having a pair of opposed side vertical edges and having a pair of horizontal edges, the liner blank being centrally cut along a line parallel to the horizontal edges, which cut extends to locations adjacent to but spaced apart a predetermined distance from both of the opposed side vertical edges, the liner providing a pair of side panel-end panel reinforcements lying, respectively, above and below the horizontal cut, folding the liner blank along said horizontal cut to dispose the reinforcement pairs in overlying relationship to each other, affixing one exterior surface of the folded liner to a side panel and an end panel of an outer container blank having four interconnected panels which constitute the four upstanding sidewalls of the completed container, and folding the remaining outer container side and end panels over the liner and affixing these two panels to the other exterior surface of said folded liner.

2. The method of claim 1 wherein said folded liner is adhesively affixed to the central two panels of the outer container blank.

3. The method of claim 1 wherein the outer container blank includes a glue flap for forming a manufacturers joint and wherein an adhesive pattern is applied to said four panels and to the glue flap of the outer container blank.

4. A fiberboard blank adapted to form an inner liner for a reinforced container when mated with an outer container having opposed side panels and end panels, said blank being rectangular and having two opposed side vertical edges of a length of approximately double the desired height of the reinforcement and two parallel horizontal edges, said blank also having a horizontal cut extending generally between said two opposed side vertical edges which cut is parallel to said horizontal edges, said out dividing said blank into two halves and each of said halves containing a vertical line of weakness dividing said half into a side panel reinforcement and an end panel reinforcement, said horizontal cut terminating a predetermined short distance from each of said two opposed side vertical edges to provide attaching means in said terminal regions, said attaching means joining said halves during the fabrication of the container but being adapted to be torn when the reinforced container is opened for use.

5. The blank of claim 4 wherein said attaching means is provided by short score lines extending from the ends of said cut to each of said opposed side edges, said score lines being colinear with said cut.

6. The blank of claim 4 wherein said predetermined distance is not greater than about 1 inch.

7. A reinforced container which is fabricated to include the blank defined in claim 4, which reinforced container comprises an outer container blank providing opposed side panels and end panels, said reinforcement blank being folded about said horizontal cut to constitute upper and lower overlying halves, means adhesively joining the side panel reinforcement and the end panel reinforcement of said lower half to the interior surface of adjacent side and end panels of said outer container blank, means adhesively joining the side panel reinforcement and the end panel reinforcement of said upper half to the interior surface of the remaining side panel and end panel of said outer container blank, and joint means connecting said outer container blank in flattened tubular configuration.

8. The reinforced container of claim 7 wherein said lower half of said reinforcement blank is attached to the central side and end panels of said outer container blank.

9. The reinforced container in accordance with claim 8 wherein both said reinforcement blank and said outer 10. The reinforced container in accordance with 5 claim 7 wherein said outer blank includes upper and lower closure flaps attached respectively to each of said side and end panels and includes a glue flap hinged to a panel at one lateral edge of said outer blank. 

1. The method of forming a fiberboard container having a reinforcing fiberboard liner, which method comprises providing a rectangular liner blank having a pair of opposed side vertical edges and having a pair of horizontal edges, the liner blank being centrally cut along a line parallel to the horizontal edges, which cut extends to locations adjacent to but spaced apart a predetermined distance from both of the opposed side vertical edges, the liner providing a pair of side panel-end panel reinforcements lying, respectively, above and below the horizontal cut, folding the liner blank along said horizontal cut to dispose the reinforcement pairs in overlying relationship to each other, affixing one exterior surface of the folded liner to a side panel and an end panel of an outer container blank having four interconnected panels which constitute the four upstanding sidewalls of the completed container, and folding the remaining outer container side and end panels over the liner and affixing these two panels to the other exterior surface of said folded liner.
 2. The method of claim 1 wherein said folded liner is adhesively affixed to the central two panels of the outer container blank.
 3. The method of claim 1 wherein the outer container blank includes a glue flap for forming a manufacturer''s joint and wherein an adhesive pattern is applied to said four panels and to the glue flap of the outer container blank.
 4. A fiberboard blank adapted to form an inner liner for a reinforced container when mated with an outer container having opposed side panels and end panels, said blank being rectangular and having two opposed side vertical edges of a length of approximately double the desired height of the reinforcement and two parallel horizontal edges, said blank also having a horizontal cut extending generally between said two opposed side vertical edges which cut is parallel to said horizontal edges, said cut dividing said blank into two halves and each of said halves containing a vertical line of weakness dividing said half into a side panel reinforcement and an end panel reinforcement, said horizontal cut terminating a predetermined short distance from each of said two opposed side vertical edges to provide attaching means in said terminal regions, said attaching means joining said halves during the fabrication of the container but being adapted to be torn when the reinforced container is opened for use.
 5. The blank of claim 4 wherein said attaching means is provided by short score lines extending from the ends of said cut to each of said opposed side edges, said score lines being colinear with said cut.
 6. The blank of claim 4 wherein said predetermined distance is not greater than about 1 inch.
 7. A reinforced container which is fabricated to include the blank defined in claim 4, which reinforced container comprises an outer container blank providing opposed side panels and end panels, said reinforcement blank being folded about said horizontal cut to constitute upper and lower overlying halves, means adhesively joining the side panel reinforcement and the end panel reinforcement of said lower half to the interior surface of adjacent side and end panels of said outer container blank, means adhesively joining the side panel reinforcement and the end panel reinforcement of said upper half to the interior surface of the remaining side panel and end panel of said outer container blank, and joint means connecting said outer container blank in flattened tubular configuration.
 8. The reinforced container of claim 7 wherein said lower half of said reinforcement blank is attached to the central side and end panels of said outer container blank.
 9. The reinforced container in accordance with claim 8 wherein both said reinforcement blank and said outer container blank are formed of corrugated fiberboard, the flutes of said corrugated fiberboard extending horizontally in one blank and vertically in the other blank.
 10. The reinforced container in accordance with claim 7 wherein said outer blank includes upper and lower closure flaps attached respectively to each of said side and end panels and includes a glue flap hinged to a panel at one lateral edge of said outer blank. 